A variety of entities provide and are preparing to provide Mobile Satellite Service (“MSS”), communications services utilizing one or more satellites. One important limitation of MSS service has been an inability to achieve suburban or urban penetration. While 2 GHz MSS satellite communications provides effective coverage of rural and remote areas, coverage in suburban and urban areas is degraded by increased obscured satellite visibility.
Recognizing the value that the deployment and availability of MSS systems would bring by improving public safety, by providing voice, data, and messaging services to unserviced areas within the United States, and by increasing competition, the U.S. Federal Communications Commission (“FCC”) issued orders permitting the use of an Ancillary Terrestrial Component (“ATC”) to MSS systems to facilitate suburban and urban penetration.
MSS systems augmented with ATC (“MSS/ATC” systems) enable a wide variety of new communication services that will lead to the deployment and availability of commercially-viable interactive mobile satellite communications. By reusing at least a portion of frequencies between satellite and terrestrial communication systems, MSS/ATC systems offer more efficient spectrum utilization and effective coverage in both urban and rural areas. U.S. Pat. No. 6,950,625, which is hereby incorporated by reference in its entirety for all purposes, describes techniques for reusing frequencies between satellite and terrestrial systems. Additionally, U.S. Pat. No. 5,394,561 discloses a mechanism for networking satellite and terrestrial networks in which the power levels of the satellite and terrestrial communications are controlled so as to minimize co-channel interference.
Existing MSS and MSS/ATC systems typically provide satellite-based voice communications; however, it is possible, as described in this disclosure, to provide additional interactive communications. For example, U.S. Pat. No. 7,017,175 (“the '175 patent”), which is hereby incorporated by reference in its entirety for all purposes, describes techniques for providing interactive digital television. Using this interactive digital television system, viewers are provided with functionality not available in conventional television systems, such as, for example, the ability to receive targeted advertising, to request additional information related to a received multicast, to place an order for merchandise or services, to obtain information off of a network (e.g., the Internet), and the like.
There are many challenges in implementing an interactive communication system, such as that described by the '175 patent, in a hybrid satellite/terrestrial communication system. There is a need for an effective design to handle multicast transmissions across both satellite and ancillary terrestrial networks, as well as to handle interactive communications for individual users. Furthermore, network characteristics, such as latency, bandwidth, throughput, and the like, vary between satellite and terrestrial networks. Thus, there is a need for a hybrid communication system to effectively use both satellite and terrestrial networks to provide effective coverage to both urban and rural subscribers.